Source: http://www.abarim-publications.com/Meaning/Achaicus.html

🔼The name Achaicus in the Bible

The name Achaicus occurs only once in the Bible. The apostle Paul mentions him among the three men who Chloe sent to him, the others being Stephanas and Fortunatus (1 Corinthians 16:17).

🔼Etymology of the name Achaicus

According to Spiros Zodhiates (The Complete Word Study Dictionary New Testament) the name Achaicus means "belonging to Achaia," and Achaia (Αχαια) is the name of the Roman province that covered the southern part of modern Greece — the northern part was called Macedonia. The city of Corinth was situated in Achaia.

The name Achaia and thus Achaicus comes from the Greek noun αχος (achos), meaning grief: